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67 Cards in this Set
- Front
- Back
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a gauge that measures preassure above atmospheric and vacum below atmospheric preassure
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compoung gauge
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amonia absrption system
1-removes water from refrigerant |
analizer
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amonia absorption
2-holds strong liquor |
generator
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amonia system
3-regulates liquor flow |
weak liquor valve
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amonia system
4-removes moisture from the vapor |
rectifier
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amonia system
5-removes vapor from evaporator |
absorber
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amonia system
type of metering device used |
manual
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in a booster system the second compressor is called
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the primary compressor
bacause it is always started first |
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in a booster system the first compressor is called
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the booster compressor
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this stores any extra refrigerant that might be in the system and keeps it available so that the expansion valve has it when needed
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receiver
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two types of cooling towers
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1- forced-pushes air in the tower
2-enduced-pulles air in the tower |
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two tipes of Brines
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1-sodium choride freezing point -6.0 fh
2-calsium chloride freezing point -59.8 fh |
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nesslers solution
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test water for amonia-turns
1-yellow for small leak 2-brown for large leak |
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a preasure reducing valve that controls the flow of refrigetrant to the evaporator
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metering device
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the most efective rust inhibitors
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chromates
1-sodium bichromate 2sodium dichromate |
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(metering device) that is a small tank conected to the evaporator with a needle valve that regulated flow
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low side float
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1-maintains the preasure diferential between the condenser and the eveporator.
2-it feeds the proper amount or refrigerant to the evaporator. 3-it responds to the load change in the system |
thermostatic expansion valve
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installed between the compressor and the condenser,as far from the compresson as possible stops oil from entering the condenser
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oil separator
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device that is temperature operates the opening or closing of the metering device.inside the valve
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internal equalizer (TEV)
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removes moisture from system
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Driers or Dehydrators
installed usually liquid line drier |
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remove air and other non-condesables from the system
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purgers
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when a preassure drop of more than 2 pounds in the evaporator you need a________in the metering device
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external equalizer
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a vessel or tank located in the suction line between evaporator and compressos to prevent cary over or slugging of liquid into the compressor
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suction line accumulator
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remove sludge,dirt,scale
installed before the compressor |
filters & strainers
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to check the operation and efficiency of the compressor
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engine indicator
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is designed to vaporize all of the low preasure liquid that passes through the evaporator
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dry evaporator
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the temp of the refrigerant must be _________the temp of the medium being cooled
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below
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chilled water is cooled by the refrigerant than circuleted to the apt the refrigerant never enters the apt this system is called?
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indirect system
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submerged below the refrigerant are tubes that carry chilled water to cool the refrigerant
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flooded evaporator
(horizontal shell & tube) |
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(metering device)located in the receiver
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higt side float
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heat will always travel from the warm mass
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to the cool mass
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heat is rejected from the refrigeraton cycle by air or water at the____________
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condenser
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metering device for systems with coonstant load
water coolres,domestic ref (constant preassure valve) |
automatic expantion valve
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remove noise & vibration
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Mufflers
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maitain the proper oil level in multiple compressor systems
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oil equilizer lines
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melts at 275 FH
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fusible plug
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made out of carbon or grafhite and designed to rupture at 15 PSI
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rupture disk
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during periods of low load the preassure drops,cutting of the compressor,it re-starts system when preasure rises
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low preasure control
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safety device it cuts off the system if the high side preassure exeeds a certain setting.it is not capable of re-starting the system
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high preasure control
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in an amonia absorbtion systen the______________acts like the compressor
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the absorber
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absorbtion system
the generator contains a continous sourse of__________ |
heat
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trouble evaporator
A-low evaporator preassure |
1-dirty coil
2-dirty evaporator filter 3-supply air short cycling 4-oil logged 5-low refrigerant charge 6-paraffin based refrigerant oil |
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trouble evaporator
B-high evaporator pressure |
1-system operating at maximum load
(max load preassure) expansion valve wide open |
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trouble evaporator
low superheat |
1-manual expancion valve needs re-adjusting
2-partially blocked expansion valve 3-dirty evaporator 4-too much refrigerant being sent to the evaporator 5-TEV sensing bulb disconected from coil |
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trouble compressor
high suction preassure,low discharge preassure(reciprocating compressor) |
compressor valves not seating properly
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trouble compressor
banging sound on start up(reciprocating compressor) |
oil over charge
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trouble compressor
oil foaming in crankcase(reciprocating compressor) |
1-crankcase heater not working
2-sudden drop in crankcase preassure |
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trouble compressor
compressor surging (centrifugal) |
1-high head preasure
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problem condenser
low head preasure |
1-condense water temp too low
2-under charge of refrigerant |
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problem condenser
high head preassure |
1-over charge of refrigerant
2-not enough condenser water 3-condenser water temp to high |
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problem liquid line
frost on liquid line |
partial blockege of liquid line
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problem liquid line
bubbles in liquid line sigth glass |
loss liquid seal
shortage of refrigerant |
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problem liquid line
liquid line warmer than usual |
loss of liquid seal
shortage of refrigerant |
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problem liquid line
presence of water in the system |
1-blocked flow at metering device
2-sigth glass moisture indicator turns color (green to yellow) |
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problen expansion valve
TEV starved evaporator |
1-external equilizer line blockage
2-broken sencing bulb 3-internally equilized TEV used on a coil with a preasure drop of more that 2.5 psi |
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problem expansion valve
TEV flooded evaporator |
sensing bulb disconnected from from coil
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problem expansion valve
AXV- starved evaporator at high load,flooded evaporator at low load |
automatic control valve used in a variable load system
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problem expansion valve
low side float-suction preasure rising |
broken / punctured float assembly
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problem expantion valve
high side float starved evaporator |
broken / puntured float assembly
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problems mechanical
noisy operation |
worn bearings
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problems mechanical
premature bearing wear/high running amps |
1-belt tension too high
2-pulley out of alignment 3-coupling out of alignment |
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motor problems electrical
open windings |
ohmmeter reads (infinity)
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motor problems electrical
shorted motor windings |
1-winding resistance less than the motors published value
2-less resistance causestemperature to rise,motor overload device opens circut(shut down) |
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motor problems electrical
short circuit to grownd |
high resistance reading
use ohmmeter or megaohmmeter |
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motor problem electrical
icorrect rotation |
reverse any two of the motor power leads
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motor problem electrical
high operating temp |
high corrent
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cetrifugal water pump problems
pump not delivering rated GPM |
1-discharge/suction valves partialy closed
2-pump air bound 3-pump cavitating 4-plugged strainer 5-piping coniguration altered 6-check valve in a parallel pump not seating properly |
